Acceleration responsive switching device

ABSTRACT

An acceleration responsive switching device which comprises a casing having, at its bottom portion, a reverse cone-shaped inner wall, a weight ball movably put in the casing and normally positioned on said reverse cone-shaped inner wall at its central portion, a switch means provided in the casing at the center of the bottom portion and being normally in contact with said weight ball and adapted to be disengaged from the contact with said ball when the ball is upwardly moved along an inclined face of said reverse cone-shaped inner wall due to an acceleration given. The present switching device is exactly and instantaneously responsive to an excessive acceleration, thereby enabling the traffic accident to be effectively avoided. The device is simple in construction and easy to manufacture at a reasonable cost.

ilriited States Patent 1' Suzuki et al.

[ 1 3,723,680 1 Mar. 27, 1973 [54] ACCELERATION RESPONSIVE SWITCHINGDEVICE [75] Inventors: Masaru Suzuki, Chiryu; Masayoshi Iwata, Hajima;Takeo Matsui, Gifu, all of Japan [22] Filed: Aug. 18, 1971 [21] Appl.No.: 173,711

[30] Foreign Application Priority Data 200/153 T, 166 BB; 340/261, 262

[56] References Cited UNITED STATES PATENTS 12/1960 Mishler ..200/6l.45R

3,621,163 11/1971 Hitchcock ..200/6l.45 M 3,379,059 4/1968 Wiley..200/61.45 M 3,578,930 5/1971 Tiefenthaler et al ..200/1 53 T PrimaryExaminerRobert K. Schaefer Assistant ExaminerM. GinsburgAttorney-Woodhams, Blanchard and Flynn [57] ABSTRACT An accelerationresponsive switching device which comprises a casing having, at itsbottom portion, a reverse cone-shaped inner wall, a weight ball movablyput in the casing and normally positioned on said reverse cone-shapedinner wall at its central portion, a switch means provided in the casingat the center ofv thebottom portion and being normally in contact withsaid weight ball and adapted to be disengaged from the contact with saidball when the ball is upwardly moved along an inclined face of saidreverse coneshaped inner wall due to an acceleration given. The presentswitching device is exactly and instantaneously responsive to anexcessive acceleration, thereby enabling the traffic accident to beeffectively avoided. The device is simple in construction and easy tomanufacture at a reasonable cost.

5 Claims, 4 Drawing Figures PATENT EDHAR271975 FIG.3

FIG.1

INVENTORS MASARU SUZUKI BY MASAYOSHI IWATA TAKEO MATSUI WOODHAMS,BLANCHARI) and FLYNN Apturncy ACCELERATION RESPONSIVE SWITCHING DEVICEThis invention relates to a switching device, and more particularly to aswitching device adapted to be provided in a movable body such as amotor car and actuated responsive to an acceleration exceeding apredetermined level.

Recently, rapid increase of road vehicles has incurred many trafficaccidents. In order to avoid such accidents, safety devices such assafety belt and air bag provided in a motor car have been put intopractical use. Of such safety devices, the rolling-up type safety beltand the air bag respectively employ a locking device and an exploderdevice which are adapted to detect an acceleration of the motor car.

In known forms of acceleration responsive switching devices, especiallyin those utilizing a weight ball, the weight ball having a magneticpermeability is used to detect an acceleration by making use of magneticflux change caused by movement of the weight ball. Such conventionaldevices require a number of parts and are complicated in structure,leading to high cost of manufacturing. Such conventional devices needalso a relatively long time to detect an acceleration and are lack ofinstant responsiveness.

An object of this invention is to provide an acceleration responsiveswitching device which is simple in construction and exactly andinstantaneously responsive to the acceleratiom Another object of thisinvention is to provide an acceleration responsive switching device ofthe character described, which requires a reduced number of elements orparts in constructions.

These and other objects, features and advantages will be apparent'tothose skilled in the art from the following detailed description and theappended claims.

Essentially, according to the present invention, there is provided anacceleration responsive switching device which comprises a casinghaving, at its bottom portion, a reverse cone-shaped inner wall, aweight ball movably put in the casing and normally positioned on saidreverse cone-shaped inner wall at its central portion, a switch meansprovided in the casing at the center of the bottom portion and beingnormally in contact with said weight ball and adapted to be disengagedfrom the contact with said ball when the ball is upwardly moved along aninclined face 'of said reverse cone-shaped inner wall due to anacceleration given.

This invention will now be more particularly described with reference tothe accompanying drawings in which:

FIG. I shows a vertically sectioned elevation of an accelerationresponsive switching device embodying this invention;

FIG. 2 is a bottom view of the device shown in FIG.

FIG. 3 shows a vertically sectional elevation of another accelerationresponsive switching device embodying this invention; and

FIG. 4 is a sectional-view of the device shown in FIG. 3 taken along theline IV-IV.

Like portions and parts are designated by like numerals in FIGS. 1 to 4.

Referring now to FIGS. 1 and 2, there is shown an accelerationresponsive switching device which comprises a cylindrical casing 1having, at its-bottom portion, a reverse cone-shaped inner wall 3. Thecasing l is closed with a closure 4 threadedly fitted into saidcasing 1. The casing 1 has also a mounting plate 2 connected integrallytherewith at the outer cylindrical side wall and adapted to be mountedon a vertical plane in the interior of a motor car at a suitable place.

In the interior of the casing l is movably put in a weight ball 5 whichis normally positioned on the inner wall 3 of the bottom at its lowestor central portion.

The casing l is provided with a vertical opening 6 at the centralportion of the bottom wall. Into said vertical opening 6 is slidablyinserted a pushing rod 8 for movement in vertical directions. Thepushing rod 8 has an upper surface 9 of a spherical shape to be snuglyin contact with spherical surface of the weight ball 5 put in thecasing 1. In the normal position, the upper sur- 7 face of the pushingrod'8 forms a part of the inner surface of the bottom wall. Said pushingrod 8 has also a bottom which is supported on a self-returning pushbutton 11 and is provided at its center with a small hole to be engagedwith the upper end of said self-returning push button 11 which extendsfrom a microswiteh l0 fixedly mounted on a suitable place, for exampleon a support plate 7 as shown in FIGS. 1 and 2. The support plate 7 isformed integrally with the casing 1 and the casing mounting plate 2, andextends from both of the bottom wall and said casing mounting plate in avertical plane at a distance from the hole 6.

The closure 4 in the casing has an inner wall having a profile to leavea space in the casing 1 to allow the weight ball to slide upwardly alongthe inclined face of the bottom wall. The inner wall of the closure 4has at its central portion a downwardly projecting part 13 whichprevents the weight ball from jumping up at the central position.Theclosure 4 is similarly constructed and functions in anotherembodiment as in FIGS. 3 and In operation, when an acceleration is givento a device-carrying motor car in a direction perpendicular to thevertical axis of the casing 1, namely in a horizontal direction, theweigh ball 5 is slidingly moved upwardly along the inclined face 3 ofthe bottom wall. Then, the weight ball 5 moves from the upper surface 9of the pushing rod 8. As a result, a pushing force is released from therod 8. Therefore the pushing rod 8 is urged upwardly by the returningforce of the pushing button 11 to allow the latter to move upwardly,whereby off-operation of the switch is completed. Once the accelerationdecreases below a predetermined level, the weight ball 5 movesdownwardly to give a pushing force onto the upper surface of the pushingrod 8. The pushing rod 8 is pushed down to in turn urge the push button11 downwardly, whereby the microswitch is caused to turn on (normalposition).

FIG. 3 and 4 show another embodiment of this invention. The illustrationof the same components or parts as employed in the foregoing embodimentis omitted to avoid repetition.

The casing l is not necessary to be provided with members such as thesupport plate 7 and the central opening as shown in FIG. 1. Instead,there are employed, at the bottom wall of the casing, two or moreelectric contacts l2, 12' connected to an electrical circuit (not shown)as depicted. The upper ends of the electric contacts are placed closelyonto the inner face 3 and normally in contact with the weight ball 5. Inoperation, a horizontal acceleration is given to a device-carrying motorcar to move the weight ball in the same manner as described referring toFIG. 1 and 2 and when the acceleration exceeds a predetermined level theweight ball 5 is caused to disengage from the connection with at leastone of the electric contacts 12, 12' whereby the electrical circuitwhich is closed through the electric contacts 12-, 12' and the weightball 5 of electrical conductive material is now forced to open. With adrop of acceleration, the weight ball 5 is returned into contact withthe contact surfaces of both electric contacts l2, 12'.

What is claimed is:

1. An acceleration responsive switch device, comprising:

casing means including a bottom wall portion having an upwardly facingand upwardly diverging conical support surface, said bottom wall portionhaving an opening extending substantially vertically therethroughsubstantially at the apex of said-conical support surface;

a ball movably supported on said support surface, the weight of saidball normally maintaining same at the apex of said conical supportsurface; and

electrical switch means adapted to be actuated by said ball when same ismoved toward to or away from said apex, said switch means includingactuator means movably positioned within said opening and positioned forengagement with said ball when said ball is located at said apex, saidactuator means being depressed by said ball when said ball is located atsaid apex. 2. A switch device according to claim 1, wherein said switchmeans comprises, a microswitch having a push button for actuating same,and said actuator means in-.

cluding a push rod slidably disposed within said opening and having theupper end thereof positioned for engagement with said ball, the lowerend of said push rod being interconnected with said button for actuatingsame.

3. A switch device according to claim 2, wherein said push button isdisposed in engagement with the lower end of said push rod, said pushbutton urging said push rod upwardly so that the upper end thereofprojects beyond said conical support surface when said ball is movedupwardly along said support surface away from said apex.

4. A switching device according to claim 2, wherein the upper end ofsaid push rod has an upper surface having a spherical shape compatiblewith the spherical configuration of said ball.

5. A switching device according to claim 1, wherein said casing meansincludes an upper wall portion disposed above and spaced from saidbottom wall portion so as to define a chamber therebetween in which ispositioned said ball, and said upper wall portion having projectionmeans fixedly secured thereto and projecting downwardly therefrom towardsaid apex, said projection means being disposed closely adjacent saidball when same is positioned at said apex for preventing said ball frommoving vertically upwardly away from said support surface.

1. An acceleration responsive switch device, comprising: casing meansincluding a bottom wall portion having an upwardly facing and upwardlydiverging conical support surface, said bottom wall portion having anopening extending substantially vertically therethrough substantially atthe apex of said conical support surface; a ball movably supported onsaid support surface, the weight of said ball normally maintaining sameat the apex of said conical support surface; and electrical switch meansadapted to be actuated by said ball when same is moved toward to or awayfrom said apex, said switch means including actuator means movablypositioned within said opening and positioned for engagement with saidball when said ball is located at said apex, said actuator means beingdepressed by said ball when said ball is located at said apex.
 2. Aswitch device according to claim 1, wherein said switch means comprisesa microswitch having a push button for actuating same, and said actuatormeans including a push rod slidably disposed within said opening andhaving the upper end thereof positioned for engagement with said ball,the lower end of said push rod being interconnected with said button foractuating same.
 3. A switch device according to claim 2, wherein saidpush button is disposed in engagement with the lower end of said pushrod, said push button urging said push rod upwardly so that the upperend thereof projects beyond said conical support surface when said ballis moved upwardly along said support surface away from said apex.
 4. Aswitching device according to claim 2, wherein the upper end of saidpush rod has an upper surface having a spherical shape compatible withthe spherical configuration of said ball.
 5. A switching deviceaccording to claim 1, wherein said casing means includes an upper wallportion disposed above and spaced from said bottom wall portion so as todefine a chamber therebetween in which is positioned said ball, and saidupper wall portion having projection means fixedly secured thereto andprojecting downwardly therefrom toward said apex, said projection meansbeing disposed closely adjacent said ball when same is positioned atsaid apex for preventing said ball from moving vertically upwardly awayfrom said support surface.